Insulator for electric wires



(No Model.)

J. P. MARTIN.

INSULATOR FOR ELECTRIC WIRES. K No. 286,946. Patented Oct. 16, 1883.

f Mnl/W 11111111lll111/lllllllllllllllllllllllllll PATENT OFFICE.

JOHN F. MARTIN, OF OHIO-AGO, ILLINOIS.

' INSULATOR FOR ELECTRIC WIRES.

SPECIFICATION forming part of Letters Patent No. 286,946,

dated October 16, 1883.

Application tiled March 1Q, 1883. (No model.)

To LZZ Lch/071i, Lb may concern:

Be it known that I, JOHN F. MARTIN, a citi- Vzen ofthe United States, residing in Chicago,

county of Cook, and State o1'l Illinois, have invented certain new and useful Improvements in Insulators for Electric Vires, ot' which the following is a speciiication.

rIhis invention relates to improvements in electric-wire insulators composed of sheet-paper or woven material rolled to form tubes which are coupled together, so as to provide for each wire oi" an underground system a sepa rate and continuous chamber.

The object of my invention is to render the tubes compact, strong, and durable, to unite the coils or layers ol" paper iirmly together, and to utilize the means employed I'or securing said layers together as a means l'or incorporating in the material a large quantity ot' some insulating compound which shall tend to render the tube water-prooi'. To such end, I place together a perforated and an imperio` rate sheet of paper or other suitable material, and alter filling the perfor-ations with some insulating-cement I roll the sheets thus united into tubular form.

In the annexed drawings, Figure l represents two sheets combined and partially7 rolled into tubular forni. Fig. 2 shows a section taken through two sheets, with the perforations in one ot' them Iilled with cement. Fig. represents one ot' the sheets having circular perforations. Fig. 4 is a section taken through Fig. 3.

Referring by letter to the several iigures of the drawings, in which like letters indicate like parts, A and B denote two sheets ot' paper, which are placed together, so that they can be manipulated as one sheet. One of these sheets is provided with slots or perforations C, which can be made of any desired shapeas, for example, oblong, as shown in Fig. 1, or circular, as in Fig. 3. The periorations are preferably arranged in parallel rows, with those of one row opposite the spaces between the perforations of the next succeeding row, but it will be evident that they could be otherwise arranged. The sheets-can be made of equal thickness, or one can be made somewhat thicker than the other, as in Fig. 2, in which the perforated sheet A is the thicker ot the two. After the sheets have been laid together, as herein shown, the perforations G are filled with some insulating compound or cement and the sheets then rolled to form a tube. rIhe cement filling holds the sheets together, and also holds them in the shape into .which they have been rolled. In this way a comparativelylarge quantity of cement is dis tributed throughout the material without increasing the thickness ofthe same, which latter would be the case it' the cement were laid on in a layer upon one ol" the sheets. The tubes thus made can be coupled together, so as to form continuous lines of tubing, the couplings being preferably composed of sleeves. which are iitted upon the ends or' the tube-sec` tions.

In other applications which I have made for Letters Patent the tube is shown made of but one sheet, and in one ot' said applications the sheet is perforated, and the pertorations iilled with cement before the sheet is rolled into tubular form. Such construction ol" tube, however, lacks the features ot' an imperforate sheet constituting the backing for the perforated sheet as herein shown.

Both sheets can be made ol" paper or some suitable woven material, or one sheet can be made of paper and the other ol" woven material, as preferred.

The cement employed will preferably consist of asi-)haltum or asphaltum combined with some suitable material, such as is generally used with asphaltum I'or the purpose of rendering it hard and durable after it dries.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, is-

An insulator for electric wires, composed of a perforated and an imperforate sheet rolled into tubular form7 with the openings ofthe perforated sheet filled with some insulating compound, substantially as described.

JOHN F. MARTIN.

Witnesses:

W. XV. ELLIOTT, JNO. G. ELLIOTT. 

